P1A6B

DTC P1A63, P1A69, P1A6A or P1A6B

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P1A63
- Starter/Generator Control Module Internal Circuit

DTC P1A69
- Starter/Generator Control Module Random Access Memory (RAM)

DTC P1A6A
- Starter/Generator Control Module Read Only Memory (ROM)

DTC P1A6B
- Starter/Generator Control Module 5 Volt Reference Circuit

Circuit/System Description

The starter/generator control module (SGCM) monitors to detect internal faults. If a fault is detected, the appropriate DTC will set.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

P1A63

The gate driver voltage fault signal is low or PWM logic error fault signal is low.

P1A69

RAM check error

P1A6A

RAM check error (calculated ROMSUM value does not match with defined value).

P1A6B

5 volt reference fault, 5 volt input AD value (2 byte) is out of the range for 100 ms.

Action Taken When the DTC Sets

P1A63, P1A69, P1A6A, P1A6B
* Stop PWM (MGU shutdown)
* APM PWM Off

Conditions for Clearing the DTC

P1A63, P1A69, P1A6A, P1A6B

Clears 30 seconds after cycle wake up signal.

Diagnostic Aids

P1A63, P1A69, P1A6A, P1A6B

Possible electrical failure at SGCM.

Circuit/System Verification

Caution: To help avoid personal injury, additional precautions must be taken prior to working on the generator control module or the generator starter. After removing the 36V battery cables from the generator battery, remove both engine wiring harness connectors from the generator control module. Wait at least 5 minutes and then remove the generator control module cover. Verify voltage levels at all 36V, 12V, and 3-phase connections, are less than 3 volts using a DMM before proceeding.

1. Verify that the latest service software is installed.
2. If DTC is current, replace the SGCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests